--- stderr --- node:assert:173 throw err; ^ AssertionError [ERR_ASSERTION]: function should not have been called at /Users/runner/work/_temp/node-v27.0.0-nightly2026-08-25e7a69c4992-slim/test/parallel/test-cluster-dgram-ipv6only.js:34 called with arguments: Error: bind EADDRINUSE 0.0.0.0:63838 at node:dgram:408:20 at node:dgram:269:9 at rr (node:internal/cluster/child:164:12) at Worker.<anonymous> (node:internal/cluster/child:114:7) at process.onInternalMessage (node:internal/cluster/utils:49:5) at process.emit (node:events:526:24) at emit (node:internal/child_process:973:14) at process.processTicksAndRejections (node:internal/process/task_queues:91:21) { errno: -48, code: 'EADDRINUSE', syscall: 'bind', address: '0.0.0.0', port: 63838 } at Socket.mustNotCall (/Users/runner/work/_temp/node-v27.0.0-nightly2026-08-25e7a69c4992-slim/test/common/index.js:569:12) at Socket.emit (node:events:514:20) at node:dgram:410:14 at node:dgram:269:9 at rr (node:internal/cluster/child:164:12) at Worker.<anonymous> (node:internal/cluster/child:114:7) at process.onInternalMessage (node:internal/cluster/utils:49:5) at process.emit (node:events:526:24) at emit (node:internal/child_process:973:14) at process.processTicksAndRejections (node:internal/process/task_queues:91:21) { generatedMessage: false, code: 'ERR_ASSERTION', actual: undefined, expected: undefined, operator: 'fail', diff: 'simple' } Node.js v27.0.0-pre node:internal/assert/utils:146 throw error; ^ AssertionError [ERR_ASSERTION]: Expected values to be strictly equal: 1 !== 0 at Worker.<anonymous> (/Users/runner/work/_temp/node-v27.0.0-nightly2026-08-25e7a69c4992-slim/test/parallel/test-cluster-dgram-ipv6only.js:17:12) at Worker.<anonymous> (/Users/runner/work/_temp/node-v27.0.0-nightly2026-08-25e7a69c4992-slim/test/common/index.js:511:15) at Worker.emit (node:events:514:20) at ChildProcess.<anonymous> (node:internal/cluster/primary:187:12) at ChildProcess.wrapper (node:events:639:12) at ChildProcess.emit (node:events:514:20) at ChildProcess._handle.onexit (node:internal/child_process:294:12) { generatedMessage: true, code: 'ERR_ASSERTION', actual: 1, expected: 0, operator: 'strictEqual', diff: 'simple' } Node.js v27.0.0-pre Command: out/Release/node /Users/runner/work/_temp/node-v27.0.0-nightly2026-08-25e7a69c4992-slim/test/parallel/test-cluster-dgram-ipv6only.js